This invention relates to an automatic performance apparatus for automatically producing such tones as auto-rhythm tones, auto-bass/chord tones, etc., and more particularly an automatic performance apparatus capable of varying the preset tempo of the automatically performed tones in relation to a variation in the operating speed of such performance operating elements as keys of one or more keyboards actuated by a performer.
As is well known in the art, an automatic performance apparatus producing auto-rhythm tones, auto-bass/chord tones, and an auto-arpeggio, and an automatic performance apparatus automatically generating a musical tone based on a prestored scale information produce the automatically performed tone at a regular speed according to a predetermined tempo. Accordingly, the automatically performed tones produced by such automatic performance apparatus are heard by listeners as mechanical musical tones which always vary at a constant speed. When such a musical tone is simultaneously produced with tones produced by depressed keys of an electronic musical instrument, even when the key operating speed is varied for the purpose of improving the musical effect, the speed of the automatically performed tone does not vary, so that it becomes impossible to keep step with the keyboard performed tone thus making it impossible to improve the musical effect.